Stability of enzymes in post-mortem rat brain.

Enzyme activities were measured in rat brains kept at room temperature for various intervals after death by decapitation. Tytosine hydroxylase, monoamine oxidase, choline acetyltransferase, and acetylcholinesterase show a substantial decline in activity over 14h reaching 64, 78, 60 and 58%, respectively. of the zero-time activity. DOPA decarboxylase, glutamic acid decarboxylase, lactate dehydrogenase, Na-K-ATPase and Mg-ATPase show less than a 15% decline in activity. The activities of most of the enzymes studied show little change time period when human brain specimens are likely between the 6th and 14th hour after death, the to be obtained for biochemical studies